(1) Field of the Invention
The present invention relates to an optical surface analysis system and method.
(2) Description of the Prior Art
An optical surface may include any surface allowing the transmission of and/or refraction of light. A curved surface describes a lens generally understood to be an optical device that transmits and/or refracts light that passes through it. The lens may converge or diverge the light passing through. Exemplary types of lenses include, but are not limited to, biconvex, biconcave, plano-convex, positive meniscus, negative meniscus, plano-concave, etc. Other types of optical surfaces include those with a flat surface. An example of a flat window surface is a periscope head window or other types of optical glass.
During normal use, the optical surface may be subjected to environmental or operational circumstances that damage it. One common form of damage includes surface defects, e.g., the optical surface may become scratched, gouged, pitted, etc. These surface defects interact with the light passing through the optical surface, thereby distorting the light, and consequently an image of the object on the opposing side. That is, a user viewing an object through an optical surface may have difficulty discerning the object clearly because of the distortions caused by the surface defects. In the case of a periscope head window, surface defects are particularly problematic because almost all objects viewed are located at great distances.
A number of prior art systems have attempted to analyze optical surfaces. In one common procedure, technicians survey the optical surface and, if significant defects are found, it is considered to be in need of replacement. This method is very subjective and often results in the optical surface being replaced, which can be cost prohibitive.
As another example, U.S. Pat. No. 8,049,879, issued to Shetterly et al. teaches an apparatus for measuring transmitted optical distribution on glass sheets. Broadly, Shetterly et al. teach projecting a light source through the glass sheet and onto a known background image having a known pattern (e.g., a series of dots). Shetterly et al., however, does not generally disclose the inventive aspects of the present disclosure.
Thus, there is a need to for an improved system and method to analyze optical surfaces, such as is identified in the present disclosure.